Over time, diabetes affects the circulatory system of the retina causing diabetic retinopathy, which occurs in about forty percent of diabetics. The earliest phase of this disease is known as background diabetic retinopathy. The next stage is known as proliferative diabetic retinopathy. In this stage, circulation problems cause areas of the retina to become oxygen-deprived or ischemic. New, fragile vessels develop as the circulatory system attempts to maintain adequate oxygen levels within the retina. Unfortunately, these delicate vessels hemorrhage easily, and blood may leak into the retina and vitreous, causing spots or floaters, along with decreased vision. In the later phases of the disease, continued abnormal vessel growth and scar tissue may cause serious problems, such as retinal detachment and glaucoma. There are several treatments for diabetic retinopathy, depending on the stage of the disease and the specific problem that requires attention. However, there still remains a need for additional treatments, especially for one that is simple to administer and which has few side effects.
Age-related macular degeneration is the leading cause of severe vision loss in people age sixty and older. There are two forms of this disease—the dry form and the wet form. The wet form accounts for only about fifteen percent of all cases, but it is responsible for most of the severe vision loss that occurs in people suffering from macular degeneration. The abnormal growth of new blood vessels (called choroidal neovascularizations) is the cause of the severe vision loss that occurs in wet macular degeneration. There is a dire need for an effective treatment for wet macular degeneration, especially for one that is simple to administer and which has few side effects.
There is also clearly a need for additional and more effective treatments for brain tumors. Therapies that are effective for other tumors currently have serious limitations as brain tumor treatments. The blood brain barrier may create a particular obstacle to the effective use of chemotherapy in the treatment of brain tumors.
Many treatments have been proposed for neurodegenerative diseases or conditions. However, most of these treatments have not been successful, and there remains a need for additional treatments for these diseases.